Self-cooling beverage container having a heat exchange unit using liquid carbon dioxide and a twist top activation system

Abstract

A self-cooling container for holding a food or beverage which includes a heat exchange unit (HEU) secured internally thereof so that the food or beverage is in contact with the outer surface of the HEU, the HEU being closed by a frangible membrane which is punctured by a pierce pin when a twist base activator is rotated in a first direction to create dis-equilibrium to cause liquid carbon dioxide contained within the HEU to pass directly from the liquid to the gaseous state and pass through a restricted orifice to atmosphere to cool the food or beverage.

1 . In a self-chilling food or beverage container ( 12 ) having a heat exchange unit ( 14 ) secured to an opening in the bottom thereof and extending into contact with the food or beverage and having a valve mechanism ( 140 - 142 ) for inserting liquid carbon dioxide into the heat exchange unit through an opening therein, the improvement characterized by
 a frangible member ( 60 - 150 ) closing the opening in the heat exchange unit;   the valve mechanism including a pierce pin system ( 56 ,  58 - 160 ,  162 ) disposed adjacent said frangible member;   a rotary activation member ( 20 - 166 ) coupled to said pierce pin system adapted to rotate only in one direction and, when so rotated, advances said pierce pin into engagement with said frangible member to pierce it to allow liquid carbon dioxide to pass from the liquid state to the gaseous state and exhaust along a flow path; and   a restricted orifice ( 75 ), disposed in said flow path and having a dimension to create a pressure drop that retains any residual carbon dioxide in the heat exchange unit in the liquid state.   
     
     
         2 . The improvement in a self-chilling food or beverage container as defined in  claim 1  wherein the pierce pin system includes a pierce plug ( 56 - 162 ) and a pierce pin ( 58 - 160 ) carried by said pierce plug and said rotary activation member ( 70 - 166 ) engages said pierce plug to rotate said pierce plug to advance said pierce pin into engagement with said frangible member. 
     
     
         3 . The improvement in a self-chilling food or beverage container as defined in  claim 2  wherein said pierce plug defines an opening ( 66 ) therein and said rotary activation member includes a finger ( 62 ) which extends into said opening in said pierce plug to rotate said pierce plug. 
     
     
         4 . The improvement in a self-chilling food or beverage container as defined in  claim 3  wherein an outer surface ( 74 ) of the pierce plug cooperates with a region ( 76 ) of an attachment adapter ( 16 ) to define said restricted orifice ( 75 ). 
     
     
         5 . The improvement in a self-chilling food or beverage container as defined in  claim 1  wherein said frangible member functions as a burst disk which is in constant contact with the liquid CO2 and will rupture when pressure within the HEU reaches a predetermined level. 
     
     
         6 . The improvement in a self-chilling food or beverage container as defined in  claim 1  wherein said rotary activation member includes ratchet teeth ( 94 ) which cooperate with ratchet legs ( 98 - 100 ) to prevent said rotary activation member from rotating in a direction other than said one direction. 
     
     
         7 . The improvement in a self-chilling food or beverage container as defined in  claim 1  wherein said rotary activation member includes a downwardly directed outer rim ( 86 ) which directs the exhausting CO2 gas flow downwardly along the outer surface of the container ( 12 ). 
     
     
         8 . The improvement in a self-chilling food or beverage container as defined in  claim 1  wherein said heat exchange unit includes a neck portion ( 28 - 128 ) having threads ( 132 ) on the outer surface thereof and which further includes an adapter ( 16 - 136 ) threadably secured to said threads on the neck of the HEU to secure the HEU to the bottom of the container. 
     
     
         9 . The improvement in a self-chilling food or beverage container as defined in  claim 8  wherein the adapter is manufactured from an engineering plastic material comprising a fiberglass filled polyacrylamide or a fiberglass fitted polyoxymethylene or a acrylonitrile butadiene styrene (ABS). 
     
     
         10 . The improvement in a self-chilling food or beverage container as defined in  claim 8  wherein said rotary activation member ( 20 - 166 ) includes a downwardly directed flange ( 88 ) having an inwardly directed wedge-shaped lip which secures the rotary activation member to the adapter. 
     
     
         11 . The improvement in a self-chilling food or beverage container as defined in  claim 8  which further includes a frangible member holder and a grub screw ( 152 ) which secures the frangible member in place in the holder. 
     
     
         12 . The improvement in a self-chilling food or beverage container as defined in  claim 11  which further includes a sealing member seated between the frangible member holder and the bottom of the adapter ( 136 ) to maintain the liquid carbon dioxide in the HEU in an equilibrium state. 
     
     
         13 . The improvement in a self-chilling food or beverage container as defined in  claim 12  wherein the adapter is hollow and further includes a valve stem ( 142 ) disposed in the hollow interior of the adapter and a spring urging the valve stem to a position to urge the frangible member into a sealing position, the valve stem being movable against the force of the spring to move the frangible member holder away from the bottom of the adapter to allow liquid carbon dioxide to be inserted into the HEU. 
     
     
         14 . The improvement in a self-chilling food or beverage container as defined in  claim 11  wherein said grub screw includes an opening therein through which the pressure in the HEU is communicated to the frangible member, the opening in the grub screw being dimensioned to throttle the pressure of released gaseous carbon dioxide in the event the frangible member ruptures as a result of increased pressure in the HEU. 
     
     
         15 . The improvement in a self-chilling food or beverage container as defined in  claim 8  which further includes a HEU support collar ( 126 ) surrounding the neck portion ( 128 ) of the HEU and seated against the HEU at one end thereof and against the bottom of the container at the other end thereof for securing the HEU to the container.